Stacked plate heat exchanger

ABSTRACT

A stacked-plate heat exchanger may include a high temperature coolant circuit having a first coolant flow therethrough, and a low-temperature coolant circuit having a second coolant flow therethrough, the first and second coolants having different temperature levels. The heat exchanger may also have heat exchanger plates stacked one on another, the first and second coolants flowing through the heat exchanger plates on one side, and a medium to be cooled flowing through the heat exchanger plates on another side. The heat exchanger plates may have an embossed partition separating the high-temperature coolant circuit and the low-temperature coolant circuit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to PCT/EP2015/068962 filed on Aug. 18, 2015, and DE 10 2014 217 920.3 filed on Sep. 8, 2014, the contents of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a stacked-plate heat exchanger, in particular an intercooler, comprising a high-temperature coolant circuit and a low-temperature coolant circuit.

BACKGROUND

In modern motor vehicles, a continuously increasing need for cooling needs to be met, for example, in the area of intercooling, with the result that the requirements for the cooling and air-conditioning systems are continuously increasing. An improved utilization of heat sources and sinks can result in a higher degree of utilization in this case and furthermore in a reduction in the fuel consumption. At the present time, cooling systems on the market for intercooling in this case frequently have a stacked-plate heat exchanger which is configured as single-stage. However, the efficiency which can be achieved with single-stage temperature control is limited. In order to improve the performance of cooling circuits, in particular for cooling fluids, such as coolant, refrigerant, oil, waste gas or charge air, it is therefore appropriate in some cases to cool or heat a fluid over two stages. However, a disadvantage of two-stage temperature control is that the use of two conventionally consecutively connected heat exchangers is associated with significantly higher costs and an increased installation space requirement.

Known from DE 10 2005 044 291 A1 is a stacked-plate heat exchanger, in particular an intercooler, comprising a plurality of elongate plates which are stacked on one another and connected to one another, for example, soldered, which delimit a cavity for conducting a medium to be cooled such as, for example, charge air, in the longitudinal direction of the plates and a further cavity for conducting a coolant, wherein the plates each have an inlet connection and an outlet connection for the medium to be cooled. In order to be able to provide a stacked-plate heat exchanger which on the one hand can be manufactured cost-effectively and on the other hand has a long lifetime at high temperatures, at least one coolant connection extends partially around a connection for the medium to be cooled.

The invention is concerned with the problem of providing an improved embodiment for a stacked-plate heat exchanger of the generic type, which enables a two-stage temperature control of a medium to be cooled with simultaneously compact design.

This problem is solved according to the invention by the subject matter of the independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

SUMMARY

The present invention is based on the general idea of providing an embossed partition at individual heat-exchanger plates of a stacked-plate heat exchanger, which is at the same time shaped or formed with the heat-exchanger plate and which serves to separate a high-temperature coolant circuit and a low-temperature coolant circuit from one another but at the same time allows these two circuits to run in a common stacked-plate heat exchanger. The stacked-plate heat exchanger according to the invention, which can be configured for example as an intercooler, thereby possesses said high-temperature coolant circuit and the afore-mentioned low-temperature coolant circuit, wherein two coolants having a different temperature level in the high-temperature coolant circuit and in the low-temperature coolant circuit on one side and a medium to be cooled, in particular charge air, on the other side, flow through the heat exchanger plates stacked one upon the other. With the stacked-plate heat exchanger according to the invention, it is possible for the first time to combine a two-stage temperature control in a single stacked-plate heat exchanger and thus achieve an extremely compact solution.

Expediently, the stacked-plate heat exchanger is configured as a counterflow cooler. In a counterflow cooler the coolant and the medium to be cooled flow in opposite directions to one another, whereby a particularly effective cooling can be achieved. In the case of cooling on the counterflow principle, the cooling effect is generally greater than in the case of the same flow directions.

Expediently, the heat exchanger plates have a circumferentially positioned edge via which they are soldered to an adjacent heat-exchanger plate, in particular arranged thereabove or therebelow, wherein the partition is connected to an edge in each case on the longitudinal end side. The partition thus runs through the respective heat-exchanger plate in the transverse direction and is connected to one edge at one end and to the opposite edge at the other end. Such a heat exchanger plate usually has the form of a rectangle, the narrow sides of which are rounded in a semi-circular manner however. The partition preferably runs centrally but can be arbitrarily displaced according to the required cooling capacity of the low-temperature coolant circuit or the high-temperature coolant circuit in the longitudinal direction of that heat exchanger plate. By this means the cooling capacity of the two circuits can be adjusted. The arrangement of the partition can be adjusted in this case comparatively easily by the corresponding positioning of a dividing web in the stamping tool.

In one advantageous further development of the solution according to the invention, in the area of the connection of the partition to the edge, a coolant inlet and/or a coolant outlet is/are provided. Usually the two semi-circularly rounded longitudinal end regions of each heat exchanger plate have a likewise semi-circular opening for the medium to be cooled, where the one opening is configured as an inlet opening and the other opening is configured as an outlet opening. In this case, coolant channels are arranged in an annular segment manner around the respective inlet or outlet opening. The medium to be cooled flows through the stacked-plate heat exchanger here whereby it initially enters through the inlet opening (medium inlet) and then flows through the individual heat exchanger plates in the longitudinal direction in order to be deflected again by 90 degrees at the opposite end and can be removed via the outlet opening (medium outlet). The coolant required for the heat exchange however flows, for example in the low-temperature circuit via the coolant inlets arranged in an annular segment shape and out again via two coolant outlets arranged in the area of the partition. In the high-temperature circuit, the coolant flows in via two coolant inlets arranged in the area of the partition, through the heat exchanger plate and out again via the coolant outlets arranged in an annular segment shape. The direction of flow of the coolant in the two circuits is in this case opposite to the flow of the medium to be cooled, for example, the charge air in order to be able to implement the counterflow principle.

The coolant inlets and/or the coolant outlets can have a triangular cross-section and their sides are aligned parallel to the partition and to the edge. Naturally in a particularly preferred embodiment of the cross-section of the coolant inlet or the coolant outlet, a right-angle triangle is formed whereby the two short sides of the respective coolant inlet or coolant outlet run parallel to the partition or to the edge. Such a cross-section of the coolant inlet or the coolant outlet can be produced comparatively simply with a corresponding stamping tool whereby naturally the corner region of the cross-sections are rounded in order in particular to be able to reduce a notch effect. Depending on how far the respective side of the triangular coolant inlet or coolant outlet extends along the partition, the continuous cross-section for the charge air or the medium to be cooled can be influenced. The shorter is the side length of the coolant inlet or the coolant outlet extending along the partition, the larger is the continuous cross-section for the medium to be cooled (charge air), with the result that smaller pressure losses can be achieved on the charge air side. Naturally, the side length of the coolant inlet or the coolant outlet along the partition on the high-temperature side can be greater than on the high-temperature side with the result that an optimized charge air distribution and an increased capacity can be achieved on the low-temperature side.

Further important features and advantages of the invention are obtained from the subclaims, from the drawings and from the relevant description of the figures by reference to the drawings.

It is understood that the aforesaid features and those to be explained hereinafter can be used not only in the combination given in each case but also in other combinations or alone without departing from the scope of the present invention.

Preferred exemplary embodiment of the invention are shown in the drawings and explained in detail in the following description, where the same reference numbers relate to the same or similar or functionally the same components.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures, in each case schematically,

FIG. 1 shows a sectional view through a stacked-plate heat exchanger according to the invention,

FIG. 2 shows a view of a heat exchanger plate of the stacked-plate heat exchanger,

FIG. 3 shows detailed views of a coolant inlet or coolant outlet of two adjacent heat exchanger plates,

FIG. 4 shows a view as in FIG. 2 but in a plane of a medium to be cooled,

FIGS. 5a-d show variously defined cross-sections of a coolant inlet or coolant outlet arranged in the area of a partition,

FIGS. 6a-c show various interconnections of the charge air flow in the stacked-plate heat exchanger according to the invention,

FIGS. 6d-F show various interconnections of the coolant flows in the stacked-plate heat exchanger according to the invention.

DETAILED DECSRIPTION

According to FIG. 1, the stacked-plate heat exchanger 1 according to the invention, which for example is configured as an intercooler, comprises a high-temperature coolant circuit HT and a low-temperature coolant circuit NT with heat exchanger plates 2 stacked one upon the other through which flow two coolants 3, 4 with different temperature levels. The coolant 3 flows with a higher temperature level compared with coolant 4 in the high-temperature coolant circuit HT whereas the coolant 4 flows with a significantly lower temperature level in the low-temperature coolant circuit NT. In the opposite direction the stacked-plate heat exchanger 1 according to the invention has the medium 5 to be cooled, for example, charge air, flowing through it so that the stacked-plate heat exchanger 1 operates on the counterflow principle.

In order to now effectively separate the high-temperature coolant circuit HT from the low-temperature coolant circuit NT and at the same time be able to accommodate both circuits HT and NT in the same stacked-plate heat exchanger 1, the heat exchanger plates 2 have an embossed partition 6 (compare FIGS. 2 to 6) which separates the high-temperature coolant circuit HT from the low-temperature coolant circuit NT.

Furthermore, all the heat exchanger plates 2 have a circumferentially positioned edge 7 via which they are soldered to an adjacent heat-exchanger plate 2 for example arranged thereunder or thereover, wherein the partition 6 is connected to the edge 7 in each case on the longitudinal end side. The partition 6 can in this case meet the respective edge 7 orthogonally, as shown for example according to the embodiments of FIGS. 2 to 5 b and 5 d and 6. Alternatively to this, it is also conceivable that the partition 6 meets the edge 7 at an acute angle, as is shown for example according to FIG. 5 c.

In the area of the connection of the partition 6 to the edge 7 one coolant inlet 8 and/or a coolant outlet 9 are/is arranged. According to the embodiments of FIGS. 1 to 5 c, the coolant inlets 8 or the coolant outlets 9 have a triangular, i.e. triangle-shaped cross-section and are aligned with their sides Y (compare FIGS. 5a to 5c ) parallel to the partition 6 and with their legs X parallel to the edge 7. The side Y of the triangular coolant inlet 8 or coolant outlet 9 aligned parallel to the partition 6 can be longer or shorter than the side X aligned parallel to the edge 7, where it is naturally also conceivable that both legs X, Y of the triangular coolant inlet 8 or the triangular coolant outlet 9 are the same length. Compared to this, the edge 7 according to FIG. 5d in the area of the partition 6 has an outward curvature with the result that the coolant inlet 8 and the coolant outlet 9 have an approximately circular-segment-like cross-section and are offset outwards.

The flow through the stacked-plate heat exchanger 1 according to the invention will be explained in more detail hereinafter.

According to FIG. 1, the medium 5 to be cooled, for example, the charge air, flows from a medium inlet 10 through the heat exchanger plates 2 to a medium outlet 11 substantially in a U shape through the stacked-plate heat exchanger 1. The low-temperature coolant circuit NT and the high-temperature coolant circuit HT flow in the opposite direction. The coolant 4 in this case initially flows via a coolant inlet 8′ over about half the heat exchanger plates 2 to the coolant outlet 9 located in the area of the partition 6, where two coolant outlets 9 are arranged on the partition 6 (compared FIG. 2) whereas the coolant inlet 8′ is arranged in an annular segment shape around the medium outlet 11. Via the coolant inlet 8, the coolant 3 flows after the partition 6 through the high-temperature coolant circuit HT through likewise about half of the heat exchanger plate 2 as far as the coolant outlet 9′ which runs in an annular segment manner around the medium inlet 10.

In the embodiments according to FIGS. 1 to 6, the partition 6 is substantially central but displaced slightly in the direction of the high-temperature coolant circuit HT with the result that the high-temperature coolant circuit HT has a shorter heat-transferring contact between the medium 5 to be cooled and the coolant 3. Naturally turbulence inserts 12 can be provided to improve the heat transfer. A displacement of the partition 6 can be achieved by a simple variation or displacement of a corresponding separating web in the relevant stamping tool for producing the heat exchanger plates 2. Naturally winglets or a corrugated rib structure can also be used to improve the heat transfer.

If FIG. 5a is examined, it can be identified that the side X running parallel to the edge 7 is configured to be longer than the side Y of the coolant outlet 9 running parallel to the partition 6, with the result that a width Z of the transmission cross-section available for the charge air can be enlarged and thus the pressure loss from the charge air side can be reduced.

Compared to this, the coolant outlet 9 according to FIG. 5b is provided with a significantly reduced side length of the side Y parallel to the partition 6, whereas the coolant inlet 8 on the high-temperature side, i.e. in the high-temperature coolant circuit HT has a longer side Y compared to this. As a result, a larger width Z of the available flow cross-section is provided for the medium 5 to be cooled, i.e. the charge air, on the low-temperature side NT, with the result that the flow rate on the low-temperature side NT can be reduced compared with the high-temperature side HT and the low-temperature-side cooling capacity can be increased.

FIG. 5c shows a partition 6 which meets the edge 7 at an acute angle, where the partition 6 is configured to be angled. The coolant 9 is thereby displaced in the direction of the low-temperature side NT where as a result of the angled partition 6 for the same cross-section, a larger available flow cross-section can be provided (larger width Z) for the medium 5 to be cooled, i.e. the charge air with the result that a lower pressure loss can be achieved on the charge air side.

In the case of the heat exchanger plate 2 according to FIG. 5d , the coolant inlet 8 and the coolant outlet 9 are shifted outwards, with the result that the entire width of the heat exchanger plate 2 (width=Z) is available for the medium 5 to be cooled, i.e. for the charge air. In this case, the edge 7 of the heat exchanger plate 2 is curved outwards in the area of the partition 6 and the coolant inlet 8 and the coolant outlet 9 have an approximately circular segment-shaped cross-section. By this means the smallest possible pressure loss can be achieved on the charge air side.

According to FIGS. 6a to 6c , possible interconnections on the charge air side, i.e. in the flow path of the medium 5 to be cooled are shown, where the variants shown can naturally also be mirrored. According to FIG. 6a , the stacked-plate heat exchanger 1 is configured in such a manner that the medium 5 to be cooled, for example, the charge air flows through it in a U shape. According to FIG. 6b , this takes place in a Z shape whereas according to FIG. 6c it takes place in a double U shape.

FIGS. 6d to 6f show possible interconnections on the coolant side, i.e. for the two coolant flows 3, 4 where mirrored variants are naturally also feasible in this case. According to FIG. 6d , flow of the coolant 3 through the high-temperature coolant circuit HT takes place in a U shape, in the same way as the coolant 4 flows through the low-temperature side NT in a U shape. Similarly this takes place in a Z shape according to FIG. 6e or a double U shape according to FIG. 6f Naturally the depicted variants of the charge air side and the coolant side can be combined arbitrarily with one another, where purely theoretically a direct-current variant (not shown) is also feasible.

With the stacked-plate heat exchanger 1 according to the invention, a compact two-stage heat exchanger can be provided where on the one hand, installation space advantages and on the other hand an optimized cooling can be achieved. 

1. A stacked-plate heat exchanger, comprising: a high-temperature coolant circuit having a first coolant flow therethrough, and a low-temperature coolant circuit having a second coolant flow therethrough, the first coolant and the second coolant having different temperature levels; heat exchanger plates stacked one on another, the first and second coolants flowing through the heat exchanger plates on one side and a medium to be cooled flowing through the heat exchanger plates on another side; wherein the heat exchanger plates have an embossed partition separating the high-temperature coolant circuit and the low-temperature coolant circuit.
 2. The stacked-plate heat exchanger according to claim 1, wherein the stacked-plate heat exchanger is configured as a counterflow cooler.
 3. The stacked-plate heat exchanger according to claim 1, wherein the heat exchanger plates each has a circumferentially positioned edge via which each heat exchanger plate is soldered to an adjacent heat exchanger plate, wherein the partition is connected to each edge on a longitudinal end side.
 4. The stacked-plate heat exchanger according to claim 3, wherein the partition meets the edge of each heat exchanger plate one of orthogonally or at an acute angle.
 5. The stacked-plate heat exchanger according to claim 3, wherein each heat exchanger plate has one of at least one coolant inlet and at least one coolant outlet is arranged in an area of a connection of the partition to the edge of the heat exchanger plate.
 6. The stacked-plate heat exchanger according to claim 5, wherein at least one of the at least one coolant inlet and the at least one coolant outlet has a triangular cross-section with a side aligned parallel to the partition and a leg aligned parallel to the edge.
 7. The stacked-plate heat exchanger according to claim 6, wherein one of: the side is one of longer or shorter than the leg; or the side and the leg are the same length.
 8. The stacked-plate heat exchanger according to claim 5, wherein the edge of each heat exchanger plate is outwardly curved in an area of the partition, and at least one of the coolant inlet and the coolant outlet has an approximately circular-segment-like cross-section.
 9. The stacked-plate heat exchanger according to claim 1, wherein the medium to be cooled flows through the heat exchanger plates in one of a U shape, a Z shape or a double U shape.
 10. The stacked-plate heat exchanger according to claim 1, wherein at least one of: the first coolant flows through the high-temperature coolant circuit in one of a U shape, a Z shape, or a double U shape; and the second coolant flows through the low-temperature coolant circuit in one of a U shape, a Z shape, or a double U shape.
 11. The stacked-plate heat exchanger according to claim 2, wherein the heat exchanger plates each has a circumferentially positioned edge via which each heat exchanger plate is soldered to an adjacent heat exchanger plate, wherein the partition is connected to each edge on a longitudinal end side.
 12. The stacked-plate heat exchanger according to claim 11, wherein the partition meets the edge of each heat exchanger plate one of orthogonally or at an acute angle.
 13. The stacked-plate heat exchanger according to claim 11, wherein each heat exchanger plate has one of at least one coolant inlet and at least one coolant outlet is arranged in an area of a connection of the partition to the edge of the heat exchanger plate.
 14. The stacked-plate heat exchanger according to claim 13, wherein at least one of the at least one coolant inlet and the at least one coolant outlet has a triangular cross-section with a side aligned parallel to the partition and a leg aligned parallel to the edge.
 15. The stacked-plate heat exchanger according to claim 14, wherein one of: the side is one of longer or shorter than the leg; or the side and the leg are the same length.
 16. The stacked-plate heat exchanger according to claim 13, wherein the edge of each heat exchanger plate is outwardly curved in an area of the partition, and at least one of the coolant inlet and the coolant outlet has an approximately circular-segment-like cross-section.
 17. The stacked-plate heat exchanger according to claim 2, wherein the medium to be cooled flows through the heat exchanger plates in one of a U shape, a Z shape, or a double U shape.
 18. The stacked-plate heat exchanger according to claim 2, wherein at least one of: the first coolant flows through the high-temperature coolant circuit in one of a U shape, a Z shape, or a double U shape; and the second coolant flows through the low-temperature coolant circuit in one of a U shape, a Z shape, or a double U shape.
 19. The stacked-plate heat exchanger according to claim 1, wherein the medium to be cooled is charge air.
 20. A stacked-plate heat exchanger, comprising: a plurality of heat exchanger plates; and an embossed partition separating the heat exchanger plates into a high-temperature coolant circuit through which a first coolant is flowable, and a low temperature coolant circuit through which a second coolant is flowable; wherein the heat exchanger plates are stacked one on another, and the first and second coolants flowing through the heat exchanger plates on one side, and a medium to be cooled flows through the heat exchanger plates on another side; wherein the heat exchanger plates each has a circumferentially positioned edge via which each heat exchanger plate is soldered to an adjacent heat exchanger plate, wherein the partition is connected to each edge on a longitudinal end side. 